bug #14573 (Error on adding auto_increment on to a column with '0' values)

mysql-test/r/auto_increment.result:
  test result
mysql-test/t/auto_increment.test:
  test case
sql/handler.cc:
  print_keydupp_error implemented
sql/handler.h:
  handler::print_keydupp_error declared
sql/share/errmsg.txt:
  error message added
sql/sql_table.cc:
  now we return different error message for auto_increment case

6 files changed, 54 insertions, 12 deletions

diff --git a/mysql-test/r/auto_increment.result b/mysql-test/r/auto_increment.result
index 525f64ea902..20936bcc10c 100644
--- a/mysql-test/r/auto_increment.result
+++ b/mysql-test/r/auto_increment.result
@@ -418,3 +418,9 @@ a	val
 2	1
 3	1
 drop table t1;
+CREATE TABLE t1 (t1 INT(10) PRIMARY KEY, t2 INT(10));
+INSERT INTO t1 VALUES(0, 0);
+INSERT INTO t1 VALUES(1, 1);
+ALTER TABLE t1 CHANGE t1 t1 INT(10) auto_increment;
+ERROR 23000: ALTER TABLE causes auto_increment resequencing, causing Duplicate entry '1' for key 'PRIMARY'
+DROP TABLE t1;
diff --git a/mysql-test/t/auto_increment.test b/mysql-test/t/auto_increment.test
index 26b103b0107..e0b024d021b 100644
--- a/mysql-test/t/auto_increment.test
+++ b/mysql-test/t/auto_increment.test
@@ -275,3 +275,14 @@ update t1 set a=2 where a=1;
 insert into t1 (val) values (1);
 select * from t1;
 drop table t1;
+
+#
+# Test key duplications with auto-increment in ALTER TABLE
+# bug #14573
+#
+CREATE TABLE t1 (t1 INT(10) PRIMARY KEY, t2 INT(10));
+INSERT INTO t1 VALUES(0, 0);
+INSERT INTO t1 VALUES(1, 1);
+--error ER_DUP_ENTRY
+ALTER TABLE t1 CHANGE t1 t1 INT(10) auto_increment;
+DROP TABLE t1;
diff --git a/sql/handler.cc b/sql/handler.cc
index b9ef05a33c2..f51e91f1882 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -1818,6 +1818,24 @@ ulonglong handler::get_auto_increment()
 }
 
 
+void handler::print_keydupp_error(uint key_nr, const char *msg)
+{
+  /* Write the duplicated key in the error message */
+  char key[MAX_KEY_LENGTH];
+  String str(key,sizeof(key),system_charset_info);
+  /* Table is opened and defined at this point */
+  key_unpack(&str,table,(uint) key_nr);
+  uint max_length=MYSQL_ERRMSG_SIZE-(uint) strlen(msg);
+  if (str.length() >= max_length)
+  {
+    str.length(max_length-4);
+    str.append(STRING_WITH_LEN("..."));
+  }
+  my_printf_error(ER_DUP_ENTRY, msg,
+                  MYF(0), str.c_ptr(), table->key_info[key_nr].name);
+}
+
+
 /*
   Print error that we got from handler function
 
@@ -1857,18 +1875,7 @@ void handler::print_error(int error, myf errflag)
     uint key_nr=get_dup_key(error);
     if ((int) key_nr >= 0)
     {
-      /* Write the duplicated key in the error message */
-      char key[MAX_KEY_LENGTH];
-      String str(key,sizeof(key),system_charset_info);
-      /* Table is opened and defined at this point */
-      key_unpack(&str,table,(uint) key_nr);
-      uint max_length=MYSQL_ERRMSG_SIZE-(uint) strlen(ER(ER_DUP_ENTRY));
-      if (str.length() >= max_length)
-      {
-	str.length(max_length-4);
-	str.append(STRING_WITH_LEN("..."));
-      }
-      my_error(ER_DUP_ENTRY, MYF(0), str.c_ptr(), table->key_info[key_nr].name);
+      print_keydupp_error(key_nr, ER(ER_DUP_ENTRY));
       DBUG_VOID_RETURN;
     }
     textno=ER_DUP_KEY;
diff --git a/sql/handler.h b/sql/handler.h
index d988e46b236..221fdf38f2b 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -864,6 +864,7 @@ public:
   virtual int ha_initialise();
   int ha_open(TABLE *table, const char *name, int mode, int test_if_locked);
   bool update_auto_increment();
+  void print_keydupp_error(uint key_nr, const char *msg);
   virtual void print_error(int error, myf errflag);
   virtual bool get_error_message(int error, String *buf);
   uint get_dup_key(int error);
diff --git a/sql/share/errmsg.txt b/sql/share/errmsg.txt
index a2bc77714bb..b3bd93f9dad 100644
--- a/sql/share/errmsg.txt
+++ b/sql/share/errmsg.txt
@@ -5842,3 +5842,6 @@ ER_WRONG_PARTITION_NAME
         swe "Felaktigt partitionsnamn"
 ER_CANT_CHANGE_TX_ISOLATION 25001
 	eng "Transaction isolation level can't be changed while a transaction is in progress"
+ER_DUP_ENTRY_AUTOINCREMENT_CASE
+        eng "ALTER TABLE causes auto_increment resequencing, causing Duplicate entry '%-.64s' for key '%-.64s'"
+
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index f890f504952..e7391b3d913 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -6323,6 +6323,20 @@ copy_data_between_tables(TABLE *from,TABLE *to,
 	  (error != HA_ERR_FOUND_DUPP_KEY &&
 	   error != HA_ERR_FOUND_DUPP_UNIQUE))
       {
+         if (error == HA_ERR_FOUND_DUPP_KEY)
+         {
+           uint key_nr= to->file->get_dup_key(error);
+           if ((int) key_nr >= 0)
+           {
+             const char *err_msg= ER(ER_DUP_ENTRY);
+             if (key_nr == 0 &&
+                 (to->key_info[0].key_part[0].field->flags & AUTO_INCREMENT_FLAG))
+               err_msg= ER(ER_DUP_ENTRY_AUTOINCREMENT_CASE);
+             to->file->print_keydupp_error(key_nr, err_msg);
+             break;
+           }
+         }
+
 	to->file->print_error(error,MYF(0));
 	break;
       }